188 / 236
Bleier et al.
TABLE 5.
Outcomes vs tumor location
Location
n
%
Intraconal (n
=
16)
Results
Complete resection
11
68.8
Partial resection
1
6.3
Biopsy
2
12.5
Decompression
2
12.5
Morbidity
New diplopia
4
25.0
New enophthalmos
4
25.0
Reconstruction
6
37.5
Extraconal (n
=
7)
Results
Complete resection
6
85.7
Partial resection
1
14.3
Biopsy
0
0.0
Decompression
0
0.0
Morbidity
New diplopia
1
14.3
New enophthalmos
1
14.3
Reconstruction
0
0.0
TABLE 6.
Diplopia vs method of medial rectus retraction
Diplopia
Method of retraction
n
%
No
None
13
76.5
Double ball probe
3
17.6
Transseptal suture
1
5.9
Yes
None
3
50.0
External
1
16.7
Transseptal suture
1
16.7
Muscle detachment
1
16.7
of our cases; however, this was generally performed in the
extraconal space. The removal of intraconal fat to improve
visualization should therefore be performed with extreme
caution because this may inadvertently traumatize the del-
icate inferomedial branches of the ophthalmic artery that
traverse medially from the main ophthalmic arterial trunk
to supply the belly of the medial rectus muscle
16
as well
as branches of the third cranial nerve. The use of a saline
soaked cottonoid (neuropatty) may be used instead to gen-
tly displace a broad area of fat and absorb blood in order to
facilitate dissection around the tumor capsule. Both warm
water irrigation and bipolar cautery were utilized success-
fully to provide hemostasis; however, the use of monopo-
lar electrocautery was avoided by all groups. Although the
precise current and proximity required to injure the optic
nerve is unknown, the literature
18
supports the blanket rec-
ommendation to avoid the use of monopolar cautery within
the orbit or in proximity to the orbital apex.
Adequate and atraumatic retraction of the medial rectus
muscle represents another important consideration when
accessing intraconal lesions. Injury to the muscle fibers,
neurovascular supply, or medial displacement may all re-
sult in postoperative muscle dysfunction and subsequent
diplopia. A range of both static and dynamic medial rec-
tus retraction methods were employed among all of the
groups. The only external method involved placing a su-
ture around the medial rectus at its insertion on the globe.
Although the presence of immediate postoperative diplopia
was evenly distributed among patients with or without re-
traction, the only method not associated with any diplopia
was the transseptal double ball technique. In this approach,
the right angle of a double ball probe is passed under the in-
ferior border of the muscle, allowing the muscle to be pulled
superomedially as needed. Despite this, the numbers are too
small to provide a meaningful recommendation regarding
the optimal method for medial rectus retraction. Regard-
less of the method utilized, however, a working knowledge
of the course of the oculomotor nerve along the lateral as-
pect of the medial rectus muscle and its ramification and
penetration of the muscle belly approximately one-third of
the distance from the annulus of Zinn to its insertion on
the globe, will help to protect this nerve from inadvertent
traction injury.
16
A complete resection was possible in the majority of
cases of both extraconal and intraconal lesions. This is
consistent with the fact that OCHs tend to be well en-
capsulated and rarely infiltrate adjacent structures.
13
As
expected, tumors located within the intraconal space were
associated with a greater incidence of incomplete removal
and postoperative morbidity including new onset diplopia
and enophthalmos. This may be attributed to the fact that
approaches to the intraconal space mandate a larger or-
bitotomy as well as a greater degree of medial rectus in-
strumentation than extraconal lesions. In light of these
technical requirements, it follows that 37.5% of patients
with intraconal lesions underwent some form of medial or-
bital reconstruction as opposed to 0.00% in the extraconal
group.
This work represents the largest reported series of purely
endoscopic endonasal resection of OCHs. The indica-
tions for this approach are currently limited to lesions lo-
cated medial to the optic nerve. However, it carries mul-
tiple advantages over open techniques including improved
visualization and illumination while providing direct access
to the lesion and reducing trauma and retraction of adjacent
normal structures. Consequently, our reported functional
outcomes are comparable or better than those reported
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